What to do...

I am in a slight dilemma...a few weeks (months?) ago my PC packed in. It's a fairly strong build with a PSU that is way too big (the source of my problems). So big in fact it has fused the electricity in my house a couple of times

Anyway, a few weeks ago (months?) my computer wouldn't turn back on, after trying for a week, it finally turned on, and in fear it would do the same...I have not turned it off...only restarted and turn off and QUICKLY on again. I will be getting a new PSU asap, but should I risk turning it off? I want to save the planet...! Is it possibly anything different that the PSU?

Ideas?